Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.36 (hyaluronidase)
 4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Facility of aqueous outflow and time-dependent changes in its hyaluronidase-sensitive and hyaluronidase-resistant components were evaluated in freshly excised canine eyes by constant pressure quantitative aqueous perfusion. Mean baseline facility of outflow was 0.24 microliter/min/mm Hg. With prolonged perfusion at constant intraocular pressure, facility of outflow was observed to increase almost linearly for at least 3 hr and continued to increase for up to 10 hr, reaching a maximum several times the initially measured facility. Perfusion with pooled dog aqueous humor did not prevent the time-dependent increase in measured facility. Rapid exchange of anterior chamber contents with perfusion solution alone produced an immediate threefold increase in facility, again followed by a gradual time-dependent facility increase. Rapid exchange of anterior chamber contents with hyaluronidase produced an immediate fivefold increase in facility with stabilization of measured facility over 3 hr and subsequent perfusion. The time-dependent changes in measured facility of outflow or "washout phenomenon" appeared to result from the gradual dissolution of the hyaluronidase-sensitive component of the barriers to aqueous outflow in the canine eye.
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PMID:The canine eye: in vitro dissolution of the barriers to aqueous outflow. 14 84

Rabbit eyes with steroid-induced ocular hypertension were investigated in order to evaluate the histochemical abnormalities in the chamber angle region. The right eye of 14 rabbits was treated by dexamethasone 1% 3 times daily for 3 to 5 weeks. The eyes were stained by haematoxylin-eosin, periodic acid Schiff, fibrin, colloidal iron, and alcian blue with and without hyaluronidase. All treated eyes developed elevated intraocular pressure up to 4 weeks after treatment. These globes showed alcian-blue-positive hyaluronidase-sensitive staining in the amorphous material adjacent to Schlemm's canal and in the cytoplasmic granules of trabecular endothelial cells. There was no increase in incorporation of radioactive thymidine into nuclei of endothelial cells as seen by autoradiography. These results provide further support for the idea that there is abnormal accumulation of acid mucopolysaccharides in the chamber angle in steroid-induced ocular hypertension.
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PMID:Ocular changes in rabbits with corticosteroid-induced ocular hypertension. 15 77

Possible interdependence of facility of aqueous outflow and intraocular pressure was examined by quantitative aqueous perfusion at four levels of intraocular pressure in 69 canine eyes, freshly excised post-mortem. Statistically similar, time-dependent increases in facility of outflow occurred over steps of increasing and decreasing, and at constant intraocular pressue. Pretreatment with intracameral hyaluronidase diminished the rate of facility increase, reducing it to 20% or less in one third of the eyes so perfused. Observed increases in canine facility of outflow with changing intraocular pressure appeared to result primarily from "washout" of the hyaluronidase-sensitive component of the barriers to aqueous outflow and not from direct effects of the intraocular pressure.
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PMID:The canine eye: in vitro studies of the intraocular pressure and facility of aqueous outflow. 64 Jul 85

Trabeculectomy fails to control the intraocular pressure (IOP) adequately in some cases. The effect of the enzyme hyaluronidase--300 IU Hylase 'Dessau' (commercially available ampuls)--applied in subconjunctival injection in the region above the filtering bleb in case of postoperative rise in IOP following trabeculectomy was studied. Successful IOP control was defined as an IOP below or equal to 20 mmHg with or without medication. The investigation concerned 62 eyes (46 patients) with primary open angle glaucoma (POAG) divided in three groups: Group I--39 eyes with early postoperative rise in IOP (7-20 days postoperatively), group II--15 eyes with late rise in IOP (6 months-1 year after surgery), group III--8 eyes with one previous unsuccessful trabeculectomy. In all examined cases IOP was over 20 mmHg (mean IOP was 26.23 +/- 3.46 mmHg) postoperatively before application of hyaluronidase. The follow up period ranged from 6 to 34 months. We found statistically significant lowering in IOP in group I (p < 0.01), group II (p < 0.05) and group III (p < 0.05). Complications related to the use of hyaluronidase were not observed up to now. Postoperative subconjunctival injection of hyaluronidase appears to improve the prognosis following unsuccessful trabeculectomy in POAG patients.
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PMID:Application of hyaluronidase after unsuccessful trabeculectomy. 147 55

Twenty patients had retrobulbar anesthesia with 5 ml mepivacaine (Scandicain) without or with addition of 150 units of hyaluronidase (Kinetin). Before and 15 min after injection, we determined--by means of oculo-oscillo-dynamography--the systolic retinal and ciliary perfusion pressures, the respective ocular blood pressures (intramural pressures) and the ocular pulsation volume (PVoc) as well as the intraocular pressure (Pio; hand-applanation tonometer). Without hyaluronidase, the ocular perfusion and blood pressures were lowered by 11.8 and 3.9 mmHg, respectively, and PVoc was reduced by 0,40 microliters, whereas Pio was increased by 7.9 mmHg With hyaluronidase, the ocular perfusion and blood pressures were decreased by averages of 12.7 and 6.8 mmHg, respectively, PVoc was reduced by 0.42 microliters, and Pio was increased by 6.0 mmHg. Within each group, all changes were significant. There were, however, no significant differences between the two groups, i.e., the "spreading factor" hyaluronidase does not influence the inhibitory effects of retrobulbar anesthesia on ocular circulation.
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PMID:[Effect of hyaluronidase on ocular circulatory changes caused by retrobulbar anesthesia]. 185 46

In 20 patients, retrobulbar injections of 2 or 5 ml local anesthetic (bupivacaine-lidocaine mixture with hyaluronidase) were given preoperatively. Directly after the 5-ml injection, the systolic retinal and ciliary perfusion pressures (measured by means of oculo-oscillo-dynamography according to Ulrich) were reduced by an average of 5.6 mmHg (p less than 0.001) in comparison with the untreated fellow eyes. The ocular pulsation volume (PVoc) was reduced by 39%. Fifteen minutes after the 5-ml injection, the perfusion pressures and PVoc were reduced even slightly more. The intraocular pressure (Pio) was increased by an average of 3.2 mmHg directly after the 5-ml injection, whereas after 15 min the Pio had reassumed its preinjection level. After the 2-ml injection, the PVoc was reduced by the same amount as found after the 5-ml injection. However, there was no significant change in perfusion pressures or Pio after the 2-ml injection. The findings observed during retrobulbar anesthesia may be interpreted as an inhibitory effect on ocular hemodynamics, which increases at higher injection volumes. This effect cannot be accounted for by adrenaline--which was not employed--and can at best only partially be accounted for by the changes in Pio.
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PMID:[Changes in uveal and retinal hemodynamics caused by retrobulbar anesthesia using various injection volumes]. 262 12

A report on 3 instances of accidental injection of lidocaine into the eye. Among the immediate reactions were (1) development of corneal edema due to an abrupt rise in intraocular pressure, (2) dilatation and paralysis of the pupil, (3) decrease of visual acuity to light perception. In 2 of the patients pupillary reaction and retinal function recovered completely; the third developed a permanent field defect. The effects of intraocular injection of lidocaine, epinephrine and hyaluronidase were subsequently studied in an animal model. The corneal and pupillary reactions of the animals correlated with those of the 3 patients. The b-wave of the electroretinogram, representing the function of the internal retinal layers, was temporarily extinguished but recovered completely after 4 hours. Subsequent light and electron microscopic study of the animal retinas did not reveal any drug induced damage. Following intraocular injection of lidocaine, epinephrine, or hyaluronidase permanent damage to the retina or irreversible reduction in visual acuity was observed neither in the first 2 patients nor in the animals.
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PMID:[Local anesthesia with accidental perforation of the eye--an acute emergency?]. 371 80

The use of sodium hyaluronate in cataract surgery and intraocular lens implantation is often followed by a postoperative rise of intraocular pressure. A trial is described in which 10 patients underwent bilateral cataract extraction and Binkhorst intraocular lens implantation with the use of sodium hyaluronate. The enzyme hyaluronidase was instilled into the anterior chamber of the right eye only, to aid removal of sodium hyaluronate, and resulted in a statistically significant lowering of postoperative intraocular pressure in right eyes compared with left. Other uses of the enzyme are discussed.
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PMID:Hyaluronidase and sodium hyaluronate in cataract surgery. 371 4

The use of intraocular sodium hyaluronate is complicated by a postoperative rise in intraocular pressure (IOP). The rise in IOP is thought to stem from a "clogging" at the trabecular meshwork by the large molecules of hyaluronate. This study uses serial tonographic measurements in an animal model to document this change in outflow facility. Furthermore, we investigate the ability of the enzyme hyaluronidase to cleave the hyaluronate into smaller molecular weight fragments, in vivo, and thereby eliminate the change in outflow facility. This report demonstrates the potential usefulness of this enzyme and documents the lack of harmful side effects histopathologically.
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PMID:Elimination of sodium hyaluronate-induced decrease in outflow facility with hyaluronidase. 380 83

Although glycosaminoglycans (GAGs) have been postulated to play a role in the regulation of intraocular pressure, structural localization of specific varieties of GAGs in the outflow system is necessary before their precise role can be determined. In this study, the outflow system of the cat was stained with ruthenium red to identify GAGs with the electron microscope. The composition of the ruthenium red-stainable material was determined by predigestion of tissues with testicular hyaluronidase, neuraminidase, or papain. Testicular hyaluronidase-sensitive GAGs were located on the surfaces of the endothelial cells in the trabecular meshwork and aqueous plexus, within their basal laminae, and in the amorphous tissue of the trabecular beams and tissue adjacent to the aqueous plexus. Collagen and elastic fibers throughout the outflow system were also associated with ruthenium red-stainable material that was resistant to testicular hyaluronidase. Connective tissue GAGs, but not endothelial cell-associated GAGs, were demonstrated to be complexed to protein, since they were disrupted by papain treatment. Neuraminidase-sensitive material (sialoglycoprotein) was identified only on the lumenal surface of the endothelial cells of the aqueous plexus. The complex distribution of GAGs and order polyanions in the outflow system of the cat suggests that the these macromolecules may serve more than one function.
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PMID:Distribution of glycosaminoglycans in the aqueous outflow system of the cat. 617 75


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